How It Works
Equine gestation averages 340 days (approximately 11 months), with a normal range of 320 to 360 days. Due date equals breeding date plus 340 days. Most mares foal between day 320 and day 360; foals born before day 320 are premature and may need veterinary intervention. Trimesters: First (days 0–113) covers embryo fixation and pregnancy check at 14–16 days. Second (days 114–226) is when fetal growth accelerates and nutrition needs increase. Third (days 227–340+) involves rapid fetal growth, udder development, and foaling preparation. Maiden mares and older mares may gestate longer, and individual variation is normal.
Foaling Preparation Checklist
60 days before due date: give rhinopneumonitis (EHV) booster if not given at months 5, 7, 9, begin increasing feed by 10–15% for third-trimester energy needs, and set up foaling stall (12×12 minimum) with clean bedding. 30 days before due date: administer core vaccines (tetanus, EEE/WEE, West Nile, rabies if not current), perform Caslick’s removal if applicable, and assemble foaling kit with towels, iodine for navel, enema, and flashlight. 14 days before due date: begin nightly foaling watch, wrap tail, and monitor udder development and waxing. Signs of imminent foaling include waxing of teats (1–2 days before), relaxation of tailhead ligaments, vulvar elongation and relaxation, and restlessness, sweating, lying down and getting up.
